A motor apparatus, comprising: a motor; and a plurality of control circuit boards (41, 42) on each of which a power circuit (41a, 42a) and a control circuit (41b, 42b) are mounted, the power circuit being configured to operate so as to supply electric power necessary to drive the motor, the control circuit being configured to control an operation of the power circuit, the plurality of control circuit boards (41, 42) being arranged with an overlapping portion (Or) to each other when viewed along an axial direction of a rotation shaft of the motor on an extension line (m) of an axis of the rotation shaft, wherein the overlapping portion of the plurality of control circuit boards (41, 42) intersects the extension line (m) of the axis of the rotation shaft, the motor apparatus further comprising a heat sink configured to promote heat dissipation of the power circuit, wherein the plurality of control circuit boards (41, 42) include a first control circuit board and a second control circuit board that are arranged across the heat sink in the axial direction of the rotation shaft, a mounting face (Spb) of the first control circuit board where a heating element (Tr) of the power circuit of the first control circuit board is mounted and a mounting face (Spb) of the second control circuit board where a heating element (Tr) of the power circuit of the second control circuit board is mounted face the heat sink, and an area on the first control circuit board where the power circuit is mounted and an area on the second control circuit board where the power circuit is mounted do not overlap each other when viewed along the axial direction on the extension line (m) of the axis of the rotation shaft. a motor; and a plurality of control circuit boards (41, 42) on each of which a power circuit (41a, 42a) and a control circuit (41b, 42b) are mounted, the power circuit being configured to operate so as to supply electric power necessary to drive the motor, the control circuit being configured to control an operation of the power circuit, the plurality of control circuit boards (41, 42) being arranged with an overlapping portion (Or) to each other when viewed along an axial direction of a rotation shaft of the motor on an extension line (m) of an axis of the rotation shaft, wherein the overlapping portion of the plurality of control circuit boards (41, 42) intersects the extension line (m) of the axis of the rotation shaft, the motor apparatus further comprising a heat sink configured to promote heat dissipation of the power circuit, wherein the plurality of control circuit boards (41, 42) include a first control circuit board and a second control circuit board that are arranged across the heat sink in the axial direction of the rotation shaft, a mounting face (Spb) of the first control circuit board where a heating element (Tr) of the power circuit of the first control circuit board is mounted and a mounting face (Spb) of the second control circuit board where a heating element (Tr) of the power circuit of the second control circuit board is mounted face the heat sink, and an area on the first control circuit board where the power circuit is mounted and an area on the second control circuit board where the power circuit is mounted do not overlap each other when viewed along the axial direction on the extension line (m) of the axis of the rotation shaft.