The present invention relates to a heat exchanger used in the indirect heat exchange between the first medium (S) and the second medium (S '), for accommodating the first medium (S) includes a jacket (3) surrounding the jacket space (M) for, arranged in the jacket space (M), the plate type heat exchanger comprising a heat exchanger block (20) and (2) cage, the heat exchanger block (20) includes a first medium the plurality of first heat transfer passage for receiving the (S) (201), said second medium (S ') of the plurality second accept has a heat transfer passage (202) has a first collector (21), the first collector (21), a first side of the heat exchanger block (20) be fixed to (20a), said second heat transfer passage (202) is fluidly connected, thereto Ri, the first has become a collector of the second medium (S ') through (21) to be able to introduce into the second heat transfer passage (202) in a second collector (22) has a second collector (22), of the heat exchanger block (20), said first side surface (20a) and the second side of the opposite side of (20b) be fixed to the second heat transfer passage (202) is fluidly connected, thereby, the second through said collector (22) a second medium (S ') of the second has become a heat transfer path (202) to be able to flow out, the second collector (22) extends across said extending direction (E) a second side surface (20b) and which, in order to flow out the second medium (S ') from said second collector (22) The first conduit extending along the extending direction (E) (41a) is, the second collector (22) in fluid connection, and wherein the through opening of the jacket (3) (O) through the are from the jacket space (M) is derived in the extending direction (E), it relates to a heat exchanger. Based on the present invention, the first collector (21) extends across the first side surface (20a) along the extending direction (E), connected to said first collector (21) has been at least one first inlet and connection piece (31) is provided, the first inlet connection piece (31), the first of the extending direction from the collector (21) (E) so that it can be introduced is branched laterally to the first inlet connection piece (31) the second through the medium (S ') the first collector (21) with respect to and is in the, and, the heat exchanger (1), the has a third collector (23) disposed in the jacket space (M), said third collector (23), At least one of the inflow connection piece (31) in fluid connection, in particular the third collector (23) is formed into a hollow spherical or hollow hemispherical.