The invention discloses an electric contact pressure gauge with a contact action keeping function or a gas density relay allowing a contact (alarm contact) to be kept. The electric contact pressure gauge comprises a shell of the electric contact pressure gauge (or the density relay), a pressure measuring element in the shell, a plurality of signal contacts of the electric contact pressure gauge, amachine core, a pointer, a dial and a connector. The electric contact pressure gauge is characterized by further comprising a holding mechanism after signal movement. In particular, through great innovation, the holding mechanism and a reset mechanism are developed and the electric-equipment arcing overpressure alarming function can be realized. When a piece of electrical equipment is arcing, anoverpressure alarm can be given if the pressure of the electrical equipment is too high. After the arcing of the electrical equipment is over, the alarm signal is always kept when the pressure of theelectrical equipment is normal, so an operator can discover the arcing phenomenon of the electrical equipment and timely deal with the arcing electrical equipment, therefore guaranteeing the safe operation of electric power.