A 63-year-old man and 57-year-old woman were in their house in Airdrie, North Lanarkshire, when the man forced his way through the front door using a bright red battering ram at around 9pm on Thursday.
He demanded a number of items before leaving empty-handed.
Detective Inspector Cameron Miller said: “Although nobody was hurt in what we believe to have been a targeted attack, this was a terrifying ordeal for the couple and has left them extremely shaken.
“We are appealing to anyone who was in the area at the time and may have seen someone matching the above description.
“Battering rams are heavy, and this one was of a distinctive colour.
“It is unknown if the suspect made off in a vehicle from the street and therefore someone in the area may have seen him on foot nearby.
“If anyone has any information we would urge you to come forward and contact us.”
The suspect is described as around 5ft 7ins, of medium build, in his late 20s and was dressed in dark clothing.
He was wearing a dark ski mask and gloves.