A water pump that minimizes defects in which cooling water flows externally is provided. The water pump is provided with a rotating shaft supported by a body via a bearing, an impeller that is disposed at one end of the rotating shaft, and a seal member that is disposed between the impeller and the bearing. A drain passage that sandwiches the seal member and communicates with a space formed on the opposite side of the impeller is formed in the body, and a reservoir is formed downstream from the drain passage. At an upper position of a wall portion that forms the reservoir, a drain hole is formed, and a water-absorbing planar member is positioned in the reservoir.