A power conversion apparatus (100, 200, 300, 400, 500), comprising: an electric circuit element configured to operate for power conversion, the electric circuit element generating heat during operation; a connection frame (103, 303, 403) including a plate-like frame portion (114, 414) having a through-hole in which the electric circuit element is disposed; a cooler attached to the electric circuit element and to the plate-like frame portion (114, 414) and configured to cool the electric circuit element by releasing into the air the heat generated by the electric circuit element in operation; wherein the connection frame (103, 303, 403) is disposed between the cooler and a capacitor (104, 204); wherein the capacitor (104, 204) is a structural member disposed in a direction perpendicular to the frame portion (114, 414) and including a capacitor element electrically connected to the electric circuit element, the capacitor (104, 204) including a first support surface and a second support surface that are external surfaces facing in opposite directions from each other and parallel to the direction perpendicular to the frame portion (114, 414); a first frame (105, 405, 505) including an end portion fixed to the connection frame (103, 303, 403) and a first attachment surface (125, 525) fixed to the first support surface; a second frame (106, 306, 406, 506) including an end portion fixed to the connection frame (103, 303, 403) and a second attachment surface (132, 532) opposed to the first attachment surface (125, 525) and fixed to the second support surface; and an electrical conductor electrically connecting the electric circuit element and the capacitor (104, 204), wherein the direction perpendicular to the frame portion (114, 414) is horizontal, wherein the first support surface is one side surface of the capacitor (104, 204) and the second support surface is another side surface of the capacitor (104, 204), and wherein the first frame (105, 405, 505) and the second frame (106, 306, 406, 506) do not cover a top surface of the capacitor (104,204). an electric circuit element configured to operate for power conversion, the electric circuit element generating heat during operation; a connection frame (103, 303, 403) including a plate-like frame portion (114, 414) having a through-hole in which the electric circuit element is disposed; a cooler attached to the electric circuit element and to the plate-like frame portion (114, 414) and configured to cool the electric circuit element by releasing into the air the heat generated by the electric circuit element in operation; wherein the connection frame (103, 303, 403) is disposed between the cooler and a capacitor (104, 204); wherein the capacitor (104, 204) is a structural member disposed in a direction perpendicular to the frame portion (114, 414) and including a capacitor element electrically connected to the electric circuit element, the capacitor (104, 204) including a first support surface and a second support surface that are external surfaces facing in opposite directions from each other and parallel to the direction perpendicular to the frame portion (114, 414); a first frame (105, 405, 505) including an end portion fixed to the connection frame (103, 303, 403) and a first attachment surface (125, 525) fixed to the first support surface; a second frame (106, 306, 406, 506) including an end portion fixed to the connection frame (103, 303, 403) and a second attachment surface (132, 532) opposed to the first attachment surface (125, 525) and fixed to the second support surface; and an electrical conductor electrically connecting the electric circuit element and the capacitor (104, 204), wherein the direction perpendicular to the frame portion (114, 414) is horizontal, wherein the first support surface is one side surface of the capacitor (104, 204) and the second support surface is another side surface of the capacitor (104, 204), and wherein the first frame (105, 405, 505) and the second frame (106, 306, 406, 506) do not cover a top surface of the capacitor (104,204).