Metering apparatus for metering ingredients of compound in particular for tyres preferably operated by gravity, comprising: a storage container defining an internal volume adapted to receive an ingredient of compounds, in particular for tyres, wherein said storage container has an inlet opening and an outlet opening, a shutter body housed in said outlet opening, rotating around a shutter axis parallel to said outlet opening and having a shutter surface having a convex profile facing towards said internal volume, a collection station of the ingredient arranged at the outlet opening and comprising a measuring device configured for generating a measurement signal indicative of the quantity of collected ingredient, a first motor member operatively connected to said shutter body in order to cause the rotation thereof around the shutter axis between an angular closed position in which said shutter surface is arranged to completely close the outlet opening and an angular open position in which said outlet opening is at least partially open at an open surface, a control unit operatively connected at least to the measuring device and to the first motor member and configured for: - calculating the maximum angular opening position of the shutter body as a function of a final quantity of ingredient to be collected in the collection station and at least one approach value (M1-M3) approaching the final quantity, - generating an opening signal addressed to the first motor member adapted to cause rotation of said shutter body from the angular closing position to the maximum angular opening position, - receiving said at least one measurement signal and - generating, as a function of the quantity of ingredient collected in the collection station, a first control signal directed to the first motor member and adapted for controlling the degree of opening of the outlet opening decreasing the degree of opening of the outlet opening causing rotation of the shutter body from the maximum angular opening position towards the angular closing position upon reaching a first approach value to the final quantity, the first control signal being adapted for modifying the modes for controlling the degree of opening of the outlet opening when at least one further approach value (M2-M3) to the final quantity is reached. a storage container defining an internal volume adapted to receive an ingredient of compounds, in particular for tyres, wherein said storage container has an inlet opening and an outlet opening, a shutter body housed in said outlet opening, rotating around a shutter axis parallel to said outlet opening and having a shutter surface having a convex profile facing towards said internal volume, a collection station of the ingredient arranged at the outlet opening and comprising a measuring device configured for generating a measurement signal indicative of the quantity of collected ingredient, a first motor member operatively connected to said shutter body in order to cause the rotation thereof around the shutter axis between an angular closed position in which said shutter surface is arranged to completely close the outlet opening and an angular open position in which said outlet opening is at least partially open at an open surface, a control unit operatively connected at least to the measuring device and to the first motor member and configured for: - calculating the maximum angular opening position of the shutter body as a function of a final quantity of ingredient to be collected in the collection station and at least one approach value (M1-M3) approaching the final quantity, - generating an opening signal addressed to the first motor member adapted to cause rotation of said shutter body from the angular closing position to the maximum angular opening position, - receiving said at least one measurement signal and - generating, as a function of the quantity of ingredient collected in the collection station, a first control signal directed to the first motor member and adapted for controlling the degree of opening of the outlet opening decreasing the degree of opening of the outlet opening causing rotation of the shutter body from the maximum angular opening position towards the angular closing position upon reaching a first approach value to the final quantity, - calculating the maximum angular opening position of the shutter body as a function of a final quantity of ingredient to be collected in the collection station and at least one approach value (M1-M3) approaching the final quantity, - generating an opening signal addressed to the first motor member adapted to cause rotation of said shutter body from the angular closing position to the maximum angular opening position, - receiving said at least one measurement signal and - generating, as a function of the quantity of ingredient collected in the collection station, a first control signal directed to the first motor member and adapted for controlling the degree of opening of the outlet opening decreasing the degree of opening of the outlet opening causing rotation of the shutter body from the maximum angular opening position towards the angular closing position upon reaching a first approach value to the final quantity, the first control signal being adapted for modifying the modes for controlling the degree of opening of the outlet opening when at least one further approach value (M2-M3) to the final quantity is reached.