It was learnt that the man, believed to be in his 30s, sustained minor cuts to his fingers and hand as he was exiting the building.
He was subsequently treated by personnel from the Fire and Rescue Emergency Response Team and paramedics who were at the scene.
A total of three fire engines and two utility vehicles manned by 24 personnel and officers from the Sembulan Fire and Rescue Department, arrived at the scene following a distress call at 1.51pm.
The fire was brought under control by 2.31pm, however, several files and office utilities were damaged by the time operation ended at about 3.31pm.
State Fire and Rescue Department Director Nordin Pauzi who was also at the scene said the sprinkler system in the office building enabled the fire to be put out quickly.
He said the cause of fire and estimated losses are being investigated.
It was learnt that the office had 45 employees who were attending a seminar at the Sabah Archives when the incident happened.
Also present was Assistant Minister to the Chief Minister Datuk Mohd Arifin Arif who said this was the first major fire incident at the Wisma Muis building, adding there were minor fire incidents in the past.
He said apart from government offices, Wisma Muis also features several shops and food outlets which can accommodate up to 1,000 at one time.
He applauded the quick action by the Fire and Rescue Department which prevented the fire from causing more damage.