Abstract: A fluid substance dispenser, includes: a main casing having a multiple number of partitioned, fluid substance storage spaces, each having a piston having a female threaded hole and a piston moving mechanism fitted inside the fluid substance storage space; a forward actuation shaft having a male thread mating the female threaded hole; and a shaft rotating mechanism for turning the forward actuation shaft. This shaft rotating mechanism is configured of a single forward-actuating knob rotatably supported by the main casing and gears for transmitting the rotation of the forward-actuating knob to each forward actuation shaft.