A fluid control mechanism includes a laser irradiation control unit to control irradiation of a light beam generated by a laser generation unit, and a liquid tank, having at least one liquid passing port and a lens to collect the light beam in the liquid tank, to hold liquid. The laser irradiation control unit emits the light beam to the lens to collect the light beam by the lens, thereby causing thermal expansion of the liquid in the liquid tank, to control inflow/outflow of the liquid via the liquid passing port.