PURPOSE: To eliminate contact of the air to be input from an exterior into an operating space with a specimen placed on an operating base.

CONSTITUTION: A safety cabinet has a cabinet body 1 having an openable door 3 on a front surface to form an operating space 2 therein, a high performance filter 6 provided at one side of the space 2 of the body 1, a blower 7 for blowing the air under pressure to the filter 6, and an operating base having a plurality of pores 8 in which the air is passed to the other side. The body 1 has a communicating passage 10 for sucking the air sucked from the pores 8 of the base by the blower 7, and an exhaust passage for discharging the air out of the body 1 to a leeward side of the blower 7 through the filter 11. The pores 8 of the base are provided in parallel with the door 3 at the door 3 side, and formed at an oblique surface 17 of a recess 15 formed at a position lower than the installation surface to be placed with the specimen 4 such as a sample of the base. The surface 17 is opposed to an opening 16 of the door 3.