To measure temperature, pressure and velocity distributions in a flow field without disturbing a flow.

This method/instrument comprises a tracer supply step A for mixing a temperature sensitive paint 1 and a pressure sensitive paint 2 as tracers 3 of fine solid particulates into the flow field to flow, an excitation step B for irradiating the temperature sensitive paint and the pressure sensitive paint respectively with specified excitation wavelengths of rays 4, 5 to bring excited states thereof, a velocity measuring step C for emitting a sheet-like beam to the flow field and for photographing images of the tracers 3 from a direction perpendicular to a sheet face to measure the velocity distribution, a temperature measuring step D for measuring light intensity I1 in a specified emitted wavelength W1 of the temperature sensitive paint 1 to measure the temperature distribution, and a pressure measuring step E for measuring light intensity I2 in a specified emitted wavelength W2 of the pressure sensitive paint 2 to measure the pressure distribution.