A portable cold and hot water supply device. A container body includes a fluid inlet, a fluid outlet, a first chamber, a second chamber, and a valve sphere. The first chamber connects to the fluid inlet and includes a circular connecting hole. The second chamber connects to the fluid outlet and connects to the first chamber via the circular connecting hole. The diameter of the valve sphere exceeds that of the circular connecting hole. The valve sphere is rotatably disposed between the first and second chambers and is detachably engaged in the circular connecting hole, controlling connection between the first and second chambers. A power supply device is electrically connected to a controller. A thermoelectric semiconductor chip abuts the second chamber of the container body and is electrically connected to the power supply device.