A power generation device driven by an engine including a crank angle detector (5, 28, 29) for detecting a crank angle, comprising: a single-phase alternating-current generator provided to be driven by a rotation of a crankshaft of the engine; a rectifier including a bridge connection of a plurality of switching elements and configured to convert alternating-current power generated by the single-phase alternating-current generator into direct-current power; and an energization controller configured to control energization switching timing for an armature winding of the single-phase alternating-current generator by the plurality of switching elements, wherein the energization controller is configured to control the direct-current power obtained by the rectifier by performing a retard angle control and an advance angle control that respectively retard and advance the energization switching timing by the plurality of switching elements with respect to a phase of an induced voltage of the single-phase alternating-current generator based on an output signal of the crank angle detector (5, 28, 29), characterized in that an upper limit value of a retard angle amount in a case in which the direct-current power obtained by the rectifier increases due to the retard angle control is set as a retard angle upper limit value, and an upper limit value of an advance angle amount in a case in which the direct-current power obtained by the rectifier decreases due to the advance angle control is set as an advance angle upper limit value, and the energization controller is configured to perform the retard angle control such that the retard angle amount with respect to the phase of the induced voltage of the single-phase alternating-current generator does not exceed the set retard angle upper limit value, and to perform the advance angle control such that the advance angle amount with respect to the phase of the induced voltage of the single-phase alternating-current generator does not exceed the set advance angle upper limit value. a single-phase alternating-current generator provided to be driven by a rotation of a crankshaft of the engine; a rectifier including a bridge connection of a plurality of switching elements and configured to convert alternating-current power generated by the single-phase alternating-current generator into direct-current power; and an energization controller configured to control energization switching timing for an armature winding of the single-phase alternating-current generator by the plurality of switching elements, wherein the energization controller is configured to control the direct-current power obtained by the rectifier by performing a retard angle control and an advance angle control that respectively retard and advance the energization switching timing by the plurality of switching elements with respect to a phase of an induced voltage of the single-phase alternating-current generator based on an output signal of the crank angle detector (5, 28, 29), characterized in that an upper limit value of a retard angle amount in a case in which the direct-current power obtained by the rectifier increases due to the retard angle control is set as a retard angle upper limit value, and an upper limit value of an advance angle amount in a case in which the direct-current power obtained by the rectifier decreases due to the advance angle control is set as an advance angle upper limit value, and the energization controller is configured to perform the retard angle control such that the retard angle amount with respect to the phase of the induced voltage of the single-phase alternating-current generator does not exceed the set retard angle upper limit value, and to perform the advance angle control such that the advance angle amount with respect to the phase of the induced voltage of the single-phase alternating-current generator does not exceed the set advance angle upper limit value.