To remove the refuse from a jet inlet opening without any access of an operator overboard a ship.

A jet propulsion device 40 for marine use such as a ship is provided with a power device to rotate a drive shaft 44. A gear device has a pinion gear 46 which is connected to the drive shaft and engaged with a pair of ring gears opposite thereto, and the ring gears are rotatable in the opposite direction by the pinion gear to selectively rotate an impeller 62 in the opposite direction. Water is sucked through a housing in a normal manner by the rotation of the impeller in the first direction to provide the thrust to an outlet opening 74. Water passing through the housing is reversed by the rotation of the impeller in the opposite direction to allow the refuse to be washed away from the impeller 62 or an inlet opening 72. An operator can remove the refuse while staying in a control station in the ship.