Coreless induction furnace

A coreless induction furnace for melting, heating or treating metals or metal melts, particularly in vacuum or under high pressure, comprising a crucible, and a cooled induction coil including a plurality of windings, a plurality of spacer means positioned between individual windings and a plurality of intermediate layers also positioned between said windings and formed of resilient gas-tight material, said intermediate layers being each positioned laterally adjacent a respective spacer means between individual windings so that each intermediate layer is closer to a central axis of said coil while said spacer means each extends to a peripheral edge of said coil, said windings together with said intermediate layers forming a portion of an outer gas-tight jacket surrounding said crucible, and a clamping device compressing said windings and said resilient intermediate layers together in an axial direction of the induction coil so that gas-tight material of said intermediate layers between said windings is compressed.