A shelf, comprising: - a rigid arm structure having a distal end; - a support element comprising one or more support surfaces to be arranged against a ceiling, said support element is provided at the distal end of the rigid arm structure; - a shelf platform connected to the rigid arm structure at a first distance from the distal end of the rigid arm structure and extending transverse relative to the rigid arm structure; and - a securing arrangement for securing the shelf to the ceiling, the securing arrangement comprising: - a securing surface arranged in connection with the rigid arm structure at a second distance from the one or more support surfaces; - a securing mechanism arranged to secure the support element via the securing surface to the ceiling; and - a securing plate having the securing surface on one side of the securing plate, said securing plate being connected to the rigid arm structure, characterised in that the rigid arm structure comprises only two arm portions (23, 24) having an outer arm surface (23a, 24a) and an inner arm surface (23b, 24b), the two arm portions (23, 24) are arranged opposite to each other such that the inner wall surfaces (23b, 24b) are at least partly facing toward each other, the securing plate is connected to the inner wall surfaces (23b, 24b) of said two arm portions (23, 24) such that the securing plate is extending between the opposite arm portions (23, 24). - a rigid arm structure having a distal end; - a support element comprising one or more support surfaces to be arranged against a ceiling, said support element is provided at the distal end of the rigid arm structure; - a shelf platform connected to the rigid arm structure at a first distance from the distal end of the rigid arm structure and extending transverse relative to the rigid arm structure; and - a securing arrangement for securing the shelf to the ceiling, the securing arrangement comprising: - a securing surface arranged in connection with the rigid arm structure at a second distance from the one or more support surfaces; - a securing mechanism arranged to secure the support element via the securing surface to the ceiling; and - a securing plate having the securing surface on one side of the securing plate, said securing plate being connected to the rigid arm structure, characterised in that the rigid arm structure comprises only two arm portions (23, 24) having an outer arm surface (23a, 24a) and an inner arm surface (23b, 24b), the two arm portions (23, 24) are arranged opposite to each other such that the inner wall surfaces (23b, 24b) are at least partly facing toward each other, the securing plate is connected to the inner wall surfaces (23b, 24b) of said two arm portions (23, 24) such that the securing plate is extending between the opposite arm portions (23, 24). - a securing surface arranged in connection with the rigid arm structure at a second distance from the one or more support surfaces; - a securing mechanism arranged to secure the support element via the securing surface to the ceiling; and - a securing plate having the securing surface on one side of the securing plate, said securing plate being connected to the rigid arm structure, characterised in that the rigid arm structure comprises only two arm portions (23, 24) having an outer arm surface (23a, 24a) and an inner arm surface (23b, 24b), the two arm portions (23, 24) are arranged opposite to each other such that the inner wall surfaces (23b, 24b) are at least partly facing toward each other, the securing plate is connected to the inner wall surfaces (23b, 24b) of said two arm portions (23, 24) such that the securing plate is extending between the opposite arm portions (23, 24).