A tonometer for measuring intraocular pressure of an examinees eye in a non-contact manner, comprises: an arithmetic part for calculating the intraocular pressure a fluid blowing unit for blowing a fluid at a cornea of the examinees eye through a nozzle a projecting optical system for projecting light onto an anterior segment of the examinees eye through the nozzle, the system including a light source and a condensing lens and an imaging optical system for imaging a cross-sectional image of the anterior segment, the system including an imaging lens and an imaging elements. The imaging optical system is placed so that extended planes of a cross section of the light projected onto the anterior segment by the projecting optical system, a principal plane of the imaging lens, and an imaging plane of the imaging element intersect one another on one axis, and the projecting optical system includes a light restriction unit that allows the light from the light source to pass through inside of the nozzle but not to pass through outside of the nozzle.
