PURPOSE: To provide the structure for the high frequency circuit package without giving hindrance to the productivity and the reliability for the connection of connection terminals of the circuit packages placed side by side with respect to the high frequency circuit package having connection terminals penetrating air-tightly the side wall and accommodating a structure circuit in its inside.

CONSTITUTION: Circuit components and integrated circuits being components of the circuit are accommodated in a package main body 9 whose one side is open and a connection terminal 1 penetrating through a surrounding side wall 92 is provided, a cover 91 is brazed to an open side to seal the internally accommodated circuit air-tightly as the circuit package 8. Two ceramic square members A2, B4 metallized and with a conductor coated to a prescribed shape are laminated and a connection terminal 1 having a step difference between an inner circuit connection face and an external connection face is formed, and the characteristic impedance of the connection terminal 1 is matched with a desired impedance by selecting the shape of the chip side conductor.