To provide a torque limiting device having a configuration in which excessive torque can be prevented from being transmitted between input-output shafts while restraining power loss and a production cost can be reduced.

A body part 30 rotationally driven by a crank shaft 10 is provided relatively rotatable in relation to a drive shaft 20 of oil pump. Within the body part 30, a first pump gear 40 fixed on the outer surface of the drive shaft 20 and a second pump gear 50 engaged with the first pump gear by circumscription are provided. A discharge opening 72 and a suction opening 71 of a gear pump 70 which is composed of the first pump gear 40 and the second pump gear 50 are connected by an annular oil passage 35. Further, a relief valve 91 to open the oil passage 35 in case when the pressure of a working oil in the discharge opening 72 of the gear pump 70 exceeds the predetermined pressure (relief pressure) is provided on the intermediate part of the oil passage 35.