The fuse is used in the medium- and high-voltage sector and has two spaced-apart power supply connections (2, 3) and an active part (1). The active part comprises a fusible, current-carrying fuse element and an arc-extinguishing medium. The fuse element is connected in an electrically conducting manner to the two power supply connections and is arranged on an electrically insulating substrate. It is of a modular construction and has at least two modules (9) connected in series. The arc-extinguishing medium covers the exposed surfaces of the fuse element. The active part is formed in the manner of a sandwich and has two stable moldings (4, 5) and a predominantly planar intermediate layer (6) arranged between the moldings (4, 5). The intermediate layer (6) contains at least the two series-connected modules, whereas a first molding (4) of the two moldings is formed at least by part of the electrically insulating substrate and the second molding (5) is formed at least by part of the arc-extinguishing medium. The fuse is distinguished by a simple construction and by favorable triggering characteristics.