An image forming apparatus comprising a liquid-cooled cooling system (10; 10a) for cooling an image forming portion whose temperature is increased by an image forming operation, using a coolant, the liquid-cooled cooling system (10; 10a) includes: a heat-receiving member disposed in thermal contact with the image forming portion and having a flow path through which the coolant flows; an inlet-side pipe attached to a coolant inlet side of the flow path in the heat-receiving member; an outlet-side pipe attached to a coolant outlet side of the flow path in the heat-receiving member; wherein the inlet-side pipe and the outlet-side pipe attached to the heat-receiving member are connected to the tube member (15a, 15b, 15c) via a joint (19a, 19b); a tube member (15a, 15b, 15c) connected between the inlet-side pipe and the outlet-side pipe for forming a circulating path for circulating the coolant through the flow path in the heat-receiving member; a pump disposed at a point along the tube member (15a, 15b, 15c) for circulating the coolant, wherein the liquid-cooled cooling system (10; 10a) further includes: a radiating unit disposed at another point along the tube member (15a, 15b, 15c) and configured to radiate heat absorbed by the coolant from the image forming portion via the heat-receiving member, wherein the joint (19a, 19b) is disposed within a space provided between the image forming portion and an electrical component drive portion for driving or controlling the image forming portion, wherein the joint (19a, 19b) is enclosed by a shielding member (21; 21a, 21b) configured to shield the joint portion from the image forming portion and the electrical component drive portion, characterized in that the joint (19a, 19b) is enclosed by the shielding member (21a, 21b) in an airtight manner. a heat-receiving member disposed in thermal contact with the image forming portion and having a flow path through which the coolant flows; an inlet-side pipe attached to a coolant inlet side of the flow path in the heat-receiving member; an outlet-side pipe attached to a coolant outlet side of the flow path in the heat-receiving member; wherein the inlet-side pipe and the outlet-side pipe attached to the heat-receiving member are connected to the tube member (15a, 15b, 15c) via a joint (19a, 19b); a tube member (15a, 15b, 15c) connected between the inlet-side pipe and the outlet-side pipe for forming a circulating path for circulating the coolant through the flow path in the heat-receiving member; a pump disposed at a point along the tube member (15a, 15b, 15c) for circulating the coolant, wherein the liquid-cooled cooling system (10; 10a) further includes: a radiating unit disposed at another point along the tube member (15a, 15b, 15c) and configured to radiate heat absorbed by the coolant from the image forming portion via the heat-receiving member, wherein the joint (19a, 19b) is disposed within a space provided between the image forming portion and an electrical component drive portion for driving or controlling the image forming portion, wherein the joint (19a, 19b) is enclosed by a shielding member (21; 21a, 21b) configured to shield the joint portion from the image forming portion and the electrical component drive portion, characterized in that the joint (19a, 19b) is enclosed by the shielding member (21a, 21b) in an airtight manner. a radiating unit disposed at another point along the tube member (15a, 15b, 15c) and configured to radiate heat absorbed by the coolant from the image forming portion via the heat-receiving member, wherein the joint (19a, 19b) is disposed within a space provided between the image forming portion and an electrical component drive portion for driving or controlling the image forming portion, wherein the joint (19a, 19b) is enclosed by a shielding member (21; 21a, 21b) configured to shield the joint portion from the image forming portion and the electrical component drive portion, characterized in that the joint (19a, 19b) is enclosed by the shielding member (21a, 21b) in an airtight manner.