A metal detector is a device used to track any trace of metal, usually found underground. It appears in the episodes "Walking Small," "Selling Out," and "Penny Foolish."


Metal detectors change in appearance throughout the series.

"Walking Small"

The metal detector is silver and has headphones.

"Selling Out" and "Penny Foolish"

The metal detector is green.

Role in series

"Walking Small"

SpongeBob uses a metal detector at Goo Lagoon. Sandals wants to use SpongeBob's metal detector, as his broke, so SpongeBob allows him to use it. However, Plankton, who is trying to teach SpongeBob to be assertive at the time, attempts to get SpongeBob to take back his metal detector, but this only helps Sandals find buried treasure.

"Selling Out"

A metal detector is used by Mr. Krabs, presumably trying to search for money on the beach. However, he gets rid of his metal detector after seeing a Help Wanted sign on the new Krabby O'Monday's restaurant.

"Penny Foolish"

A metal detector is used once again by Mr. Krabs who is searching SpongeBob's house for a penny. SpongeBob catches Mr. Krabs in the act and even wonders why Mr. Krabs isn't wearing his "metal detector handling gloves."