PURPOSE: To permit to move water inexpensively by solar energy without using energy necessary for driving the pump by a method wherein hot-water is produced by solar heat and the shape-memory of a shape-memory alloy is taken out by the temperature of the hot-water.

CONSTITUTION: A diaphragm 3, capable of reciprocating in up-and-down directions, is provided on the upper surface of a semi-elliptical case 4, the shape-memory alloy 1 is inserted into a transparent tube 2, capable of reciprocating in up-and-down, the outer peripheral bottom of the transparent tube 2 is bonded to the upper surface of the diaphragm 3, the transparent tube 2 is extended to penetrate the case 4 and reverse flow preventing valves 6, 7 are arranged at the tip end of the tube 2. The temperature of water in the transparent tube 2 is risen by sun shine, the alloy 1 is changed so as to have a high-temperature shape and water in a pump 8 flows out through the reverse flow preventing valve 7. Upon the last time of a high-temperature change, the alloy 1 compresses a low temperature tube 5 to flow the water in the low temperature tube 5 into the transparent tube 2 and the alloy 1 is cooled to a low temperature of deform it into a low temperature memory. By repeating above operations, the water in the pump enters through the reverse flow preventing valve 6 and flows out of the reverse flow preventing valve 7, thus, the pump may be used as a spraying feed water pump or the like by the very inexpensive device.