A hydraulic hammering device, comprising: - a transmission member configured to transmit a propulsive force toward a crushing target side to a tool; - a hammering mechanism configured to strike a blow on a rear portion of the transmission member; - a pushing piston disposed immediately behind the transmission member, the pushing piston having a smaller propulsive force than a propulsive force of a device main body of the hydraulic hammering device; - a damping piston positioned behind the pushing piston and disposed to slide reciprocally against the pushing piston in forward and backward directions, the damping piston having a greater propulsive force than the propulsive force of the device main body of the hydraulic hammering device; - a pushing chamber configured to be supplied with hydraulic fluid from a fluid supply source to provide the pushing piston with the smaller propulsive force; - a damping chamber configured to be supplied with hydraulic fluid from a fluid supply source to provide the damping piston with the greater propulsive force; - a drain circuit configured to discharge a leakage of hydraulic fluid from a location of sliding contact between the pushing piston and the damping piston to a tank; characterised in that the hydraulic hammering device further comprises: - a direction-restrictor (8, 9) provided in a high-pressure circuit between the damping chamber and the pushing chamber, and the fluid supply source, the direction-restrictor being configured to restrict an outflow of hydraulic fluid from the damping chamber side and the pushing chamber side to the fluid supply source side, while allowing an inflow of hydraulic fluid from the fluid supply source side to the damping chamber side and the pushing chamber side; and - a throttle provided in the drain circuit. - a transmission member configured to transmit a propulsive force toward a crushing target side to a tool; - a hammering mechanism configured to strike a blow on a rear portion of the transmission member; - a pushing piston disposed immediately behind the transmission member, the pushing piston having a smaller propulsive force than a propulsive force of a device main body of the hydraulic hammering device; - a damping piston positioned behind the pushing piston and disposed to slide reciprocally against the pushing piston in forward and backward directions, the damping piston having a greater propulsive force than the propulsive force of the device main body of the hydraulic hammering device; - a pushing chamber configured to be supplied with hydraulic fluid from a fluid supply source to provide the pushing piston with the smaller propulsive force; - a damping chamber configured to be supplied with hydraulic fluid from a fluid supply source to provide the damping piston with the greater propulsive force; - a drain circuit configured to discharge a leakage of hydraulic fluid from a location of sliding contact between the pushing piston and the damping piston to a tank; - a direction-restrictor (8, 9) provided in a high-pressure circuit between the damping chamber and the pushing chamber, and the fluid supply source, the direction-restrictor being configured to restrict an outflow of hydraulic fluid from the damping chamber side and the pushing chamber side to the fluid supply source side, while allowing an inflow of hydraulic fluid from the fluid supply source side to the damping chamber side and the pushing chamber side; and - a throttle provided in the drain circuit.