An impact drive type actuator (10) is comprised of a wire-shaped shape memory alloy (11) which contracts upon being electrified and heated, a disk-shaped insulating heat conductor (12) which contacts this wire-shaped shape memory alloy (11) and releases the heat which is generated at the wire-shaped shape memory alloy, and a drive circuit (16, 17) which instantaneously electrifies the wire-shaped shape memory alloy and instantaneously makes the wire-shaped shape memory alloy contract. According to this impact drive type actuator, it realizes a heat conduction structure which gives rise to a high heat dispersion action by the heat characteristics of the shape memory alloy, so it becomes possible to utilize the deformation by extension and contraction of a shape memory alloy which has a wire-shaped form, improve the speed and response of the deformation operation characteristics, and improve practicality.