A torque limiter, comprising: a shaft member; and a tubular member rotatably fitted onto the shaft member, wherein the tubular member has: a fluid pressure expansion chamber configured to press a peripheral face of the one of the tubular member and the shaft member against a peripheral face of the other one of the tubular member and the shaft member; a discharge passage that provides communication between the fluid pressure expansion chamber and an outside, and that has a valve seat; and a valve element arranged on the valve seat in the discharge passage, wherein when the tubular member rotates relative to the shaft member from a state where the tubular member is stationary with respect to the shaft member, the valve element is displaced from a first position for maintaining a fluid pressure in the fluid pressure expansion chamber to a second position for discharging liquid from the fluid pressure expansion chamber to the outside, wherein the valve element has a body portion; and when the body portion makes metal contact with the valve seat at the first position, the fluid pressure in the fluid pressure expansion chamber is maintained, the valve element has a projecting portion that projects from an outer face of the body portion, and that projects outward in a radial direction of the tubular member in a state where the fluid pressure in the fluid pressure expansion chamber is maintained, characterized in that the shaft member has a projecting press portion that overlaps with the projecting portion in a circumferential direction if seen in the longitudinal direction; and when the tubular member rotates relative to the shaft member, the projecting press portion presses the projecting portion to displace the projecting portion in the circumferential direction, so that the valve element is moved from the first position to the second position. a shaft member; and a tubular member rotatably fitted onto the shaft member, wherein the tubular member has: a fluid pressure expansion chamber configured to press a peripheral face of the one of the tubular member and the shaft member against a peripheral face of the other one of the tubular member and the shaft member; a discharge passage that provides communication between the fluid pressure expansion chamber and an outside, and that has a valve seat; and a valve element arranged on the valve seat in the discharge passage, wherein when the tubular member rotates relative to the shaft member from a state where the tubular member is stationary with respect to the shaft member, the valve element is displaced from a first position for maintaining a fluid pressure in the fluid pressure expansion chamber to a second position for discharging liquid from the fluid pressure expansion chamber to the outside, wherein the valve element has a body portion; and when the body portion makes metal contact with the valve seat at the first position, the fluid pressure in the fluid pressure expansion chamber is maintained, the valve element has a projecting portion that projects from an outer face of the body portion, and that projects outward in a radial direction of the tubular member in a state where the fluid pressure in the fluid pressure expansion chamber is maintained, characterized in that a fluid pressure expansion chamber configured to press a peripheral face of the one of the tubular member and the shaft member against a peripheral face of the other one of the tubular member and the shaft member; a discharge passage that provides communication between the fluid pressure expansion chamber and an outside, and that has a valve seat; and a valve element arranged on the valve seat in the discharge passage, wherein when the tubular member rotates relative to the shaft member from a state where the tubular member is stationary with respect to the shaft member, the valve element is displaced from a first position for maintaining a fluid pressure in the fluid pressure expansion chamber to a second position for discharging liquid from the fluid pressure expansion chamber to the outside, wherein the valve element has a body portion; and when the body portion makes metal contact with the valve seat at the first position, the fluid pressure in the fluid pressure expansion chamber is maintained, the valve element has a projecting portion that projects from an outer face of the body portion, and that projects outward in a radial direction of the tubular member in a state where the fluid pressure in the fluid pressure expansion chamber is maintained, characterized in that the shaft member has a projecting press portion that overlaps with the projecting portion in a circumferential direction if seen in the longitudinal direction; and when the tubular member rotates relative to the shaft member, the projecting press portion presses the projecting portion to displace the projecting portion in the circumferential direction, so that the valve element is moved from the first position to the second position.