An electric power steering device, comprising: a motor; and a control device, wherein the motor includes a case having a cylindrical shape which is opened at one end portion, wherein the control device includes: a control device main body; a connector connected to the control device main body; and a housing having a cylindrical shape which is opened at one end portion and closed at another end portion, wherein the housing houses the control device main body, wherein the case and the housing are coupled to each other in a state in which an outer peripheral end portion at the one end portion of the case and an outer peripheral end portion at the one end portion of the housing face each other, characterized in that a first sealing material is disposed between the outer peripheral end portion of the case and the outer peripheral end portion of the housing, wherein the connector has four surfaces which form an outer periphery of the connector and is disposed between the outer peripheral end portion of the case and the outer peripheral end portion of the housing, wherein a second sealing material is disposed between the housing and the three surfaces facing the housing among of the four surfaces which form an outer periphery of the connector, wherein the first sealing material is disposed between the remaining one surface of the connector and the outer peripheral end portion of the case, and wherein a part of the first sealing material disposed between the outer peripheral end portion of the case and the outer peripheral end portion of the housing and a part of the second sealing material disposed between the housing and the surface of the connector adhere to each other in a region where the sealing materials intersect. a motor; and a control device, wherein the motor includes a case having a cylindrical shape which is opened at one end portion, wherein the control device includes: a control device main body; a connector connected to the control device main body; and a housing having a cylindrical shape which is opened at one end portion and closed at another end portion, a control device main body; a connector connected to the control device main body; and a housing having a cylindrical shape which is opened at one end portion and closed at another end portion, wherein the housing houses the control device main body, wherein the case and the housing are coupled to each other in a state in which an outer peripheral end portion at the one end portion of the case and an outer peripheral end portion at the one end portion of the housing face each other, characterized in that a first sealing material is disposed between the outer peripheral end portion of the case and the outer peripheral end portion of the housing, wherein the connector has four surfaces which form an outer periphery of the connector and is disposed between the outer peripheral end portion of the case and the outer peripheral end portion of the housing, wherein a second sealing material is disposed between the housing and the three surfaces facing the housing among of the four surfaces which form an outer periphery of the connector, wherein the first sealing material is disposed between the remaining one surface of the connector and the outer peripheral end portion of the case, and wherein a part of the first sealing material disposed between the outer peripheral end portion of the case and the outer peripheral end portion of the housing and a part of the second sealing material disposed between the housing and the surface of the connector adhere to each other in a region where the sealing materials intersect.