Formwork for the production of a concrete element, in particular, a wall or ceiling element, with an opening, in particular a window or door opening, comprising: - a formwork panel, - an opening formwork with at least two frame elements to delimit at least two portions of the opening, with at least two support brackets for supporting the at least two frame elements and with a mounting element for mounting the at least two support brackets, whereby the mounting element comprises at least two mounting points for mounting the at least two support brackets, - a formwork-stripping device for transferring the opening formwork from a formwork position to form the opening into a formwork-stripping position for releasing the concrete element, - whereby the formwork-stripping device comprises a sliding and tilting mechanism for sliding the frame element in one direction parallel to the formwork panel and for tilting the respective frame element about a pivot axis extending substantially parallel to the formwork panel, whereby the sliding and tilting mechanism of the formwork-stripping device comprises a longitudinal guide and a guide element slidably and pivotably mounted therein, whereby the longitudinal guide is provided on one of the support bracket and mounting element and the guide element is provided at the other of the support bracket and mounting element, - a securing element for securing the support bracket in the formwork position, - whereby the mounting element comprises at least one first wedge surface and the securing element comprises at least one second wedge surface, wherein in the secured state of the securing element the second wedge surface of the securing element rests on the first wedge surface of the mounting element. - a formwork panel, - an opening formwork with at least two frame elements to delimit at least two portions of the opening, with at least two support brackets for supporting the at least two frame elements and with a mounting element for mounting the at least two support brackets, whereby the mounting element comprises at least two mounting points for mounting the at least two support brackets, - a formwork-stripping device for transferring the opening formwork from a formwork position to form the opening into a formwork-stripping position for releasing the concrete element, - whereby the formwork-stripping device comprises a sliding and tilting mechanism for sliding the frame element in one direction parallel to the formwork panel and for tilting the respective frame element about a pivot axis extending substantially parallel to the formwork panel, whereby the sliding and tilting mechanism of the formwork-stripping device comprises a longitudinal guide and a guide element slidably and pivotably mounted therein, whereby the longitudinal guide is provided on one of the support bracket and mounting element and the guide element is provided at the other of the support bracket and mounting element, - a securing element for securing the support bracket in the formwork position, - whereby the mounting element comprises at least one first wedge surface and the securing element comprises at least one second wedge surface, wherein in the secured state of the securing element the second wedge surface of the securing element rests on the first wedge surface of the mounting element.