A relief valve (100) is provided with a sphere (20) that separates from a seat member (10) when the pressure of working oil from a supply passage (11) reaches a set pressure, and a sphere support member (30) that is urged by an urging member (40) to support the sphere (20). The sphere support member (30) has a holding concavity (31) for holding the sphere (20), and a tapered part (32) formed in the periphery of the holding concavity (31) and inclined so as to deepen toward the holding concavity (31).
