A port for replenishing ink on the side of a main ink tank advances and the nose or tip end of a main body of a pipe enters an ink replenishing opening on the side of a sub ink tank. When a valve body in the main body of the pipe and a valve on side of the sub ink tank are pressed with each other, a communicating port is opened by the valve body. When the main body of the pipe is further inserted into the ink replenishing opening, the valve is separated from a projection portion of a gasket, and a space therebetween starts to be widened. At this stage, as a lip portion of the gasket is not in contact with an outer peripheral portion of the main body of the pipe, an ink channel is opened to the atmosphere, the ink which is remained in or adhered to the outer peripheral portion of the main body of the pipe or an inside of the ink replenishing opening is absorbed into the sub ink tank dye ti a negative pressure in the sub ink tank. Namely, the present invention provides an ink replenishing device which can reliably prevent ink dirt from being caused by ink replenishing and an ink jet recording apparatus which is provided with the ink replenishing device.