NEEDLELESS INJECTOR, METHOD OF ADJUSTING ON-COMPLETION REACHED DEPTH WITH NEEDLELESS INJECTOR, AND EJECTION PARAMETER CALCULATION PROGRAM FOR NEEDLELESS INJECTOR
A needleless injector pressurizes a substance to be injected having an ejection pressure defined as a pressure of the substance to be injected ejected through an ejection port. The ejection pressure is raised to a first peak pressure after pressurizing is started, is lowered to a pressure lower than the first peak pressure afterward, and then is raised to a second peak pressure again. An on-completion reached depth that is an on-completion reached depth of the substance when the pressurizing portion completes pressurizing is adjustable, the on-completion reached depth being increased along with increase of the first peak pressure and being increased along with reduction of a length between peaks from a first timing at which the ejection pressure reaches the first peak pressure to a second timing at which the ejection pressure reaches the second peak pressure.