Pour 1-1/2 cups water into the inner liner pot of the Instant Pot.
Add the trivet that came with the Instant Pot.
Place the corn on the cob on top of the trivet.
Close the lid and turn the release valve to the SEALING position.
Press MANUAL or PRESSURE COOK for 2 minutes on high pressure for fresh corn and 4 minutes for frozen corn. (NOTE: It will take several minutes to come up to pressure before it starts the 2 minute countdown.)
After it has pressure cooked for 2 minutes, it will beep 10 times. Let it release pressure naturally (NATURAL RELEASE) for 5 minutes.
Move the release valve to the VENTING position to do a QUICK RELEASE.
Open the lid and carefully remove the corn using tongs.
Place the corn on the cob in a serving bowl or platter or in individual serving dishes. Slather with butter and salt and enjoy!