Five anti-coal protesters walked into the building where the Victorian cabinet was meeting on Monday and chained themselves to a ladder, unimpeded by security.

The protest lasted five hours and ended when Energy Minister Michael O'Brien agreed to meet with two of the protesters.

They brought their own ladder to 1 Treasury Place in Melbourne, where Premier Ted Baillieu has his office, and used D-locks and thumb cuffs to chain themselves to it.

The group was calling for the state government not to invest in HRL Limited's proposed dual brown coal and gas demonstration plant at Morwell in the Latrobe Valley.

Northcote High School music teacher Shaun Murray, one of the protesters who met with Mr O'Brien, said he was pleased the minister was forced to meet with the group.