To provide a shape memory alloy actuator with heating means having more heating efficiency than heating means of a direct energization type or a nichrome wire wound type and less deterioration and being easy to install and miniaturizable.

An electrically heated bulb 4 such as a halogen bulb is arranged at the center of a coiled shape memory alloy 1 provided on a base 3 and it can be energized at the outside. A cylindrical reflecting member 5 is arranged around the shape memory alloy 1 and its inner peripheral surface is formed as a reflecting mirror surface 6. During non-energization of the electrically heated bulb 4, the shape memory alloy is cold and its total length is short, and so an operated member 2 is put in the condition of being placed on the reflecting member 5. Upon energizing the electrically heated bulb 4, its radiated heat gives direct heat to the shape memory alloy 1 and the radiated heat passing therethrough is reflected from the surrounding reflecting mirror surface 6 to give efficient heat to the shape memory alloy. Thus, the total length of the coiled shape memory alloy is increased to cause the operated member to be operated.