John Murphy, 52, failed to arrive at work after leaving his home in the Dennistoun area at 07:00 on 12 May.
At a police news conference, his son, also called John, said: "Our family is not the same without him and we just want him to come home."
Mr Murphy is about 5ft 8in tall, of medium build, with short brown hair, which is turning grey.
He is usually clean shaven and on the day he went missing was believed to have been wearing a cream polo shirt, black cargo trousers, black work boots and a black fleece jacket.
After leaving his home in Craigpark Drive, Mr Murphy had headed towards Duke Street to catch a bus to work.
At the news conference, also attended by Mr Murphy's wife Patricia and sister Sharon McNab, Mr Murphy jnr said: "My dad is a good man, a quiet guy, likes his football and has had his season ticket for 20 years
"It's been horrible, we don't know anything short of him coming out of a shop. You think it'll never happen to you."
He added: "The support we have had has been unbelievable and I'd like to thank everyone for all their support, knowing there are still people out there looking for him means a lot."
Police officers have been speaking to people in and around the Duke Street area in the past week in the hope of gaining new information.
A dedicated email address, JohnMurphyMissingPerson@Scotland.pnn.police.uk, has been set up to encourage members of the public to report possible sightings.
More than 100 sightings have been reported and followed up so far.
Ch Insp David Pettigrew said: "John's family is understandably upset and distraught at not having heard from him over such a lengthy period.
"They just want to know he is safe and well. He is close to his family and it's completely out-of-character for him not to be in contact with them.
"Despite the passage of time, we continue to have a dedicated team of officers working on this inquiry and I would also like to remind members of the public that the search for John goes on and if they have any information or knowledge, then please do get in touch with us."
The family of a missing Glasgow man have appealed for help to trace him, six months after his disappearance.