A lip type seal is provided with an outer ring part (31) which is tightly fitted to a seal installation part (12) of a housing (1); a seal main body (32) which is fixed to the outer ring part (31) and whose inner circumferential part extending in a bent state to the side of a sealed space (A) is sealably brought into slidable contact with an outer circumferential surface of a rotary shaft (2) inserted in the housing (1); a rear surface support plate (33) which is arranged on the rear side of the seal main body and whose outer circumferential part together with the seal main body (32) is fixed to the outer ring part (31); and a movable support plate (34) which is engaged movably in a radial direction between the seal main body (32) and the rear surface support plate (33) and whose inner diameter is clearance fitted to the outer circumferential surface of the rotary shaft (2). Therefore, such a gap in which the seal main body (32) enters is not formed between the inner circumferential surface of the movable support plate (34) and the outer circumferential surface of the rotary shaft (2).