A pressure measuring and flow-rate controlling device includes: a flattening plate including a fluid cavity in the flattening plate a flexible contact membrane provided on said flattening plate a support member configured to secure the flattening plate against a sample a pressure adjuster an inlet tube connected to the pressure adjuster at a first end of the inlet tube, the inlet tube connected to a first end of the fluid cavity at a second end opposite to the first end of the inlet tube and an outlet tube connected to a second end opposite of the first end of the fluid cavity, where the pressure adjuster is configured to control a flow rate of a fluid passing through the fluid cavity based on cell pressure of the sample.
