Ravindra Phadke, a resident of Nahar Nagar in Malad West, used his licensed revolver and shot one round through right temple area, a senior police official said.
Phadke was rushed to a local hospital where he succumbed to his injuries, he said.
According to police, a suicide note saying,"I am fed up from life and committing suicide. No one should be held responsible for this act" was found from the spot.
A case under relevant sections of IPC has been registered in the regard and investigations are underway, the official said.