To make easy confirmation operation of measuring history of biological information.

A tonometer body 3 includes a recording section 11 for recording a plurality of measured blood pressure values, a display section 5 for displaying the measured blood pressure values of a number or less which can be recorded by the recording section 11, an input section 4 continuously or stepwise selecting the measured blood pressure values to be shown in the display section 5 among the measured blood pressure values recorded in the recording section 11, and a control section 10 controlling the display section 5 so as to display the measured blood pressure values selected by the input section 4.