Provided is a injection equipment capable of alleviating the force required of a user to inject a medical liquid. A housing chamber S1 for extrusion and a housing chamber S2 for injection are mutually connected so that, when one of the chambers S1, S2 expands, the other one of the chambers contracts. As a result of switching a switching valve 9 to an open position in a state where at least a predetermined amount of the medical liquid is filled in the housing chamber S2, the housing chamber S2 for injection is contracted based on the expansion of the housing chamber S1 for extrusion according to the discharge pressure of the medical liquid pump 2 so as to deliver a predetermined amount of medical liquid.