A hopper for a coffee grinder machine (M) comprising: a main container body for containing coffee beans to be ground, wherein the main body comprises an upper loading opening ; a lower hopper portion comprising a bottom opening to allow coffee beans to reach grinding organs (G), a closing device for closing the bottom opening , wherein the closing device comprises an actuating member , a shutter member , an actuation plane (A) and a shutter plane (S), wherein the shutter plane (S) is arranged below the actuation plane (A), wherein the shutter member comprises: a single circular sector fixed with respect to the lower hopper portion , wherein the fixed circular sector comprises a central angle (α) less than 180° and a central hole ; mobile circular sectors hinged at the central hole , wherein the mobile circular sectors are rotatable between a first position in which the bottom opening is open and at least two of the sectors are substantially stacked one on top of the other in correspondence with the single fixed circular sector and a second position in which the lower opening is closed by the single fixed circular sector and by the mobile sectors arranged in a circumferential succession arrangement, wherein the closing device comprises a tubular body projecting downwards from the hopper at the bottom opening and a cup-shaped body and wherein the shutter plane (S) substantially corresponds to the bottom of the cup-shaped body . a main container body for containing coffee beans to be ground, wherein the main body comprises an upper loading opening ; a lower hopper portion comprising a bottom opening to allow coffee beans to reach grinding organs (G), a closing device for closing the bottom opening , wherein the closing device comprises an actuating member , a shutter member , an actuation plane (A) and a shutter plane (S), wherein the shutter plane (S) is arranged below the actuation plane (A), wherein the shutter member comprises: a single circular sector fixed with respect to the lower hopper portion , wherein the fixed circular sector comprises a central angle (α) less than 180° and a central hole ; mobile circular sectors hinged at the central hole , wherein the mobile circular sectors are rotatable between a first position in which the bottom opening is open and at least two of the sectors are substantially stacked one on top of the other in correspondence with the single fixed circular sector and a second position in which the lower opening is closed by the single fixed circular sector and by the mobile sectors arranged in a circumferential succession arrangement, wherein the closing device comprises a tubular body projecting downwards from the hopper at the bottom opening and a cup-shaped body and wherein the shutter plane (S) substantially corresponds to the bottom of the cup-shaped body . a single circular sector fixed with respect to the lower hopper portion , wherein the fixed circular sector comprises a central angle (α) less than 180° and a central hole ; mobile circular sectors hinged at the central hole , wherein the mobile circular sectors are rotatable between a first position in which the bottom opening is open and at least two of the sectors are substantially stacked one on top of the other in correspondence with the single fixed circular sector and a second position in which the lower opening is closed by the single fixed circular sector and by the mobile sectors arranged in a circumferential succession arrangement, wherein the closing device comprises a tubular body projecting downwards from the hopper at the bottom opening and a cup-shaped body and wherein the shutter plane (S) substantially corresponds to the bottom of the cup-shaped body . <EOS>