Andrew Sokolowski says he bought a Surface with 32 gigabytes of storage last week. But he quickly ran out of space after loading it with music and Microsoft Word documents.
He discovered that half of the 32GB storage space was being used by the operating system and pre-installed apps.
Sokolowski filed the suit Tuesday at the Superior Court in Los Angeles. He is seeking class action status.
Microsoft says on its website that the 32GB Surface has 16GB of free space while the 64GB version has 45GB free.
Microsoft didn't immediately respond to a request for comment.