The fire started around 6 pm in the area of Bullard and Music avenues.
The Clovis Fire Department says the man may have been living inside the shed.
A Clovis police officer responded to the scene within minutes with the fire department following closely behind.
The officer grabbed a fire extinguisher and tried to get to the man in the shed, but the fire had gotten too large.
"After (the fire department) put the fire out, they ended up confirming that there was one adult male in his 70s deceased inside the shed," said Clovis Police Lt. Scott Borsch.
The Clovis Police Department is handling the death investigation.
Officials are still working to figure out what caused the fire.
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