Fifty flights were delayed or diverted as the radar went down at Bangkok's Suvarnabhumi airport on Thursday for half an hour, forcing Transport Minister Charupong Ruangsuwan to make a public apology and order the investigation.
Local media reports said air traffic controllers used radios to guide planes manually during the radar blackout, which occurred after back-up power supply failed.
"Although we agreed it's a technical issue... to regain public confidence I have ordered setting up of panel headed by Transport permanent secretary and academics to carry out investigation," Charupong said.
Speaking on a weekly programme on state-run television he said engineers tried to use a spare battery to maintain the power supply but could not prevent the thirty-minute loss of radar.
"Flights were delayed for an average 30 minutes to 70 minutes and 13 flights diverted to other airports," he said, apologising to those "affected and inconvenienced.".
The company operating the radar system at Suvarnabhumi and other airports, said flights were diverted to Chiang Mai, Phuket, Kuala Lumpur and Siem Reap in Cambodia.