Abstract: A relief valve 1 includes: a housing 6 connected to a supply-side connection pipe 4a and a discharge-side connection pipe 5a and has an inflow port 61c and an outflow port 62c; a valve seat (an opening rim 61a) provided in the housing 6; a main valve body 7 which is placed in the housing 6, and capable of cutting off communication between the inflow port 61c and the outflow port 62c in the housing 6 by being seated on the valve seat (the opening rim 61a); and a biasing member 8 that biases the main valve body 7 toward the valve seat (the opening rim 61a), wherein the inflow port 61c is provided in the housing 6 such that the inflow port 61c is decentered with respect to a central axis line of the main valve body 7 in a direction in which a supply pipe 4 extends.