A shelf, comprising: a first element and a second element, fixable to one another; fixing means (4, 5, 9) for enabling the first element to be fixed to the second element; the first element comprising at least a seating at a first surface (20, 21) thereof; the fixing means (4, 5, 9) comprising at least a fixing pin, associable to the second element at a second surface (310, 320) thereof; the seating of the first element being conformed such as to receive the pin; in which the fixing means (4, 5, 9) further comprise: elastic means, associable to the pin and fixable to the second element at the second surface (310, 320), such that the pin is mobile along a first direction perpendicular to the second surface (310, 320), from a non-operative position to an operative position, in which respectively it does not engage the seating and it can engage the seating; guide means, arranged at the second surface (310, 320) of the second element, associable to the pin and conformed such that the pin is contained internally of the guide means when it is in the non-operative position thereof, and partly projects from the guide means when in the operative position thereof; the first element and the second element being positionable in such a way that the pin, when moving into the operative position thereof, engages the seating and causes the fixing of the first element to the second element; wherein the seating develops along a second direction, perpendicular to the first direction, and conforms a channel which is delimited by a bottom and by lateral surfaces; the open top of the channel being at the first surface (20, 21) of the first element; wherein the bottom exhibits at least a straight first portion and at least a second portion at least at an end of the channel, which develops up to the top of the channel with a different inclination with respect to the first portion, such as to enable removing the pin from the channel; characterized in that the shelf further comprising a blocking element, positionable and fixable internally of the channel such as to block the pin once inserted in the channel; the blocking element comprising an abutment for encountering the pin; and in that the second portion of the channel exhibits a curved profile with a concavity thereof facing towards the top of the channel. a first element and a second element, fixable to one another; fixing means (4, 5, 9) for enabling the first element to be fixed to the second element; the first element comprising at least a seating at a first surface (20, 21) thereof; the fixing means (4, 5, 9) comprising at least a fixing pin, associable to the second element at a second surface (310, 320) thereof; the seating of the first element being conformed such as to receive the pin; in which the fixing means (4, 5, 9) further comprise: elastic means, associable to the pin and fixable to the second element at the second surface (310, 320), such that the pin is mobile along a first direction perpendicular to the second surface (310, 320), from a non-operative position to an operative position, in which respectively it does not engage the seating and it can engage the seating; guide means, arranged at the second surface (310, 320) of the second element, associable to the pin and conformed such that the pin is contained internally of the guide means when it is in the non-operative position thereof, and partly projects from the guide means when in the operative position thereof; the first element and the second element being positionable in such a way that the pin, when moving into the operative position thereof, engages the seating and causes the fixing of the first element to the second element; the seating develops along a second direction, perpendicular to the first direction, and conforms a channel which is delimited by a bottom and by lateral surfaces; the open top of the channel being at the first surface (20, 21) of the first element; wherein the bottom exhibits at least a straight first portion and at least a second portion at least at an end of the channel, which develops up to the top of the channel with a different inclination with respect to the first portion, such as to enable removing the pin from the channel; characterized in that the shelf further comprising a blocking element, positionable and fixable internally of the channel such as to block the pin once inserted in the channel; the blocking element comprising an abutment for encountering the pin; and in that the second portion of the channel exhibits a curved profile with a concavity thereof facing towards the top of the channel.