An electric suspension device for a motorcycle for absorbing shocks between a vehicle body frame and a rear wheel (Wr), the electric suspension device comprising: a cylinder including an inner tube filled with oil, a piston that partitions an interior of the inner tube into a first inner oil chamber and a second inner oil chamber; a damping force adjusting valve; and a damping force adjusting motor to adjust an opening degree of the damping force adjusting valve; characterized in that the cylinder includes an outer tube surrounding the inner tube, the outer tube defining around the inner tube an outer oil chamber (Cout) that is continuous with the second inner oil chamber, the cylinder arranged to be supported on the vehicle body frame so as to be rotatable about a mounting axis extending in a left-right direction of the electric suspension device; the electric suspension device further comprises: a sub-tank including an interior partitioned into an oil chamber (Coil) filled with oil and a gas chamber (Cgas) filled with gas; a first oil passage disposed outside the inner tube and the outer tube, the first oil passage being arranged to connect the first inner oil chamber and the outer oil chamber (Cout); and a second oil passage disposed outside the inner tube and the outer tube, the second oil passage being arranged to connect the first inner oil chamber and the oil chamber (Coil) of the sub-tank; the damping force adjusting valve is provided to apply resistance to oil flowing through the first oil passage; and the first oil passage and the second oil passage share a portion with each other, and an entirety of the first oil passage and an entirety of the second oil passage are disposed on a same side with respect to a reference plane that is orthogonal to the mounting axis and includes a center line of the cylinder. a cylinder including an inner tube filled with oil, a piston that partitions an interior of the inner tube into a first inner oil chamber and a second inner oil chamber; a damping force adjusting valve; and a damping force adjusting motor to adjust an opening degree of the damping force adjusting valve; the cylinder includes an outer tube surrounding the inner tube, the outer tube defining around the inner tube an outer oil chamber (Cout) that is continuous with the second inner oil chamber, the cylinder arranged to be supported on the vehicle body frame so as to be rotatable about a mounting axis extending in a left-right direction of the electric suspension device; the electric suspension device further comprises: a sub-tank including an interior partitioned into an oil chamber (Coil) filled with oil and a gas chamber (Cgas) filled with gas; a first oil passage disposed outside the inner tube and the outer tube, the first oil passage being arranged to connect the first inner oil chamber and the outer oil chamber (Cout); and a second oil passage disposed outside the inner tube and the outer tube, the second oil passage being arranged to connect the first inner oil chamber and the oil chamber (Coil) of the sub-tank; a sub-tank including an interior partitioned into an oil chamber (Coil) filled with oil and a gas chamber (Cgas) filled with gas; a first oil passage disposed outside the inner tube and the outer tube, the first oil passage being arranged to connect the first inner oil chamber and the outer oil chamber (Cout); and a second oil passage disposed outside the inner tube and the outer tube, the second oil passage being arranged to connect the first inner oil chamber and the oil chamber (Coil) of the sub-tank; the damping force adjusting valve is provided to apply resistance to oil flowing through the first oil passage; and the first oil passage and the second oil passage share a portion with each other, and an entirety of the first oil passage and an entirety of the second oil passage are disposed on a same side with respect to a reference plane that is orthogonal to the mounting axis and includes a center line of the cylinder.