Police and firefighters were called to the scene, a warehouse belonging to J.L. Development in Moo 4, Srisoonthorn, just before 7:30am.
Soon to arrive at the scene firefighters from Srisoonthorn and Cherng Talay Municipalities.
Firefighters took over 30 minutes to bring the fire under control. Fortunately, no injuries or fatalities were reported.
The facility, used for growing cannabis, had an automated electrical system for water and temperature control, which is believed to have malfunctioned, police said.
Forensic officers are conducting further investigations to confirm the exact cause of the blaze, but at this stage the fire is suspected to have started from an electrical short circuit, with initial damage centred on the control cabinet and circuit board.
The warehouse was rented by 29-year-old Mr Isarapong (surname withheld), who had been cultivating cannabis for about a year, police noted.
The fire has caused significant financial loss, estimated to exceed B3mn, police said.