PROBLEM TO BE SOLVED: To provide a tonometer capable of measuring an intraocular pressure of an eye to be examined without causing a subject and persons around to feel noise or without air-blowing to the eye to be examined.SOLUTION: A non-contact eye ball excitation type tonometer includes: a parametric loudspeaker 30 configured so that an acoustic wave is oriented to the surface of an eye to be examined 31 a detection device 32 for detecting vibration data 34 of the eye to be examined 31 to the acoustic wave from the parametric loudspeaker 30 and a processing device for calculating an intraocular pressure of the eye to be examined 31 from the vibration data 34 of the eye to be examined 31.