The invention provides a rolling bearing with seal. Under the condition that negative pressure acts on an outer side of a seal lip, if the negative pressure is higher, the sealing pressure of the seal lip on an inner race is higher than that in common times, and the seal area does not change even when the seal surface is worn. The seal lip (43) is disposed in a protruding manner on the inner periphery of a lip supporting portion (42) of a seal member (34), comprising: a cylindrical seal surface (43a) in close contact with an outer peripheral surface of an inner race (30), and an outer side surface (43c) and an inner side surface (43b) standing upright respectively from an outer end and an inner end of the seal surface and reaching the lip supporting portion. The outer side surface is a perpendicular surface standing upright from the outer end of the seal surface in a direction perpendicular to a generating line of the outer peripheral surface of the inner race. The inner side surface includes: a perpendicular surface standing upright from the inner end of the seal surface in parallel with the outer side surface; and a conical surface inclined toward the outer side surface extending outward in a radial direction from an outer peripheral end of the perpendicular surface.