It is an object of the present invention to provide a power semiconductor device, which is capable of being operable regardless of thermal stress generation, reducing a heat generation from wire, securing the reliability of bonding portion when the device is used for dealing with a large amount current and/or under a high temperature atmosphere, a method of manufacturing the device and a bonding wire. In a power semiconductor device in which a metal electrode (die electrode 3) on a power semiconductor die 2 and another metal electrode (connection electrode 4) are connected by metal wire 5 using wedge bonding connection, the metal wire is Ag or Ag alloy wire of which diameter is greater than 50 μm and not greater than 2 mm and the die 3 has thereon one or more metal and/or alloy layers, each of the layer(s) being 50 Å or more in thickness and a metal for the layer is selected from Ni, Cr, Cu, Pd, V, Ti, Pt, Zn, Ag, Au, W and Al.