To make a tilt cylinder device more compact by providing a delay mechanism inside a hollow piston rod.

An external oil passage 61 for communicating an oil chamber S6 with an oil chamber S7 is provided outside a cylinder 51. A pump 72 and a control valve 73 are disposed in the external oil passage 61. A communication passage 34 for communicating the oil chambers S6 and S7 is formed in a piston 13. Further, a first relief valve 15 which opens when a pressure of the rod side oil chamber S6 exceeds a predetermined value is provided to the communication passage 34. A delay mechanism 16 which delays a closing operation of the first relief valve by pressing a valve 15b of the first relief valve 15 toward an open side for a predetermined time after the first relief valve 15 opens is provided inside a hollow piston rod 14.