A liquid-cooled-type cooling device includes a casing having a cooling-liquid inlet and a cooling-liquid outlet, and an outflow pipe connected to the cooling-liquid outlet. The casing includes a cooling-liquid outflow portion, and the cooling-liquid outlet is formed in a top wall of the cooling-liquid outflow portion. The outflow pipe has a bottom wall parallel to a portion of the top wall of the cooling-liquid outflow portion where the cooling-liquid outlet is formed. The bottom wall has a through hole for communication with the cooling-liquid outlet. A guide portion is provided on a portion of an upper surface of a bottom wall of the cooling-liquid outflow portion, the portion corresponding to the cooling-liquid outlet, so as to change, toward an upward direction, the flow direction of cooling liquid flowing into the cooling-liquid outflow portion. Thus, a flow resistance which cooling liquid undergoes when flowing out of the casing can be reduced.