A portable device (2,3,4,5,6) for harvesting small fruits from plants by causing a vibration or a shaking movement, comprising: - an elongated support configured to be grasped by an operator and having a longitudinal axis and an enlarged end portion that is widened with respect to the longitudinal axis; - two comb-like elements (30',30"), each comprising: - respective elongated base members (31',31") extending along respective base directions (37',37"); - respective arrays of fingers that extend from said respective elongated base members (31',31") on a same side, opposite to said elongated support, with respect to said respective elongated base members (31',31"), wherein each of said two comb-like elements (30',30") has a first hinge portion that is pivotally connected to said enlarged end portion, and a second hinge portion that is arranged at a lever distance from said first hinge portion; - an actuation unit configured for actuating an alternating rotational movement of said comb-like elements (30',30") with respect to said enlarged end portion about said respective first hinge portions, wherein said actuation unit is mounted to said elongated support; - a movement transmission mechanism between said actuation unit and said two comb-like elements (30',30"), comprising two links, each pivotally connected to said second hinge portion of a respective comb-like element (30',30") of said two comb-like elements, characterized in that said transmission mechanism also comprises: - a transmission stem comprising: - a first end portion connected to said actuation unit; - a second end portion, opposite to said first end portion, connected to a pin arranged at said second end portion of said transmission stem; said transmission stem connected to a first end of each of said two links by said pin, so that said second end portion, through both said links, causes said comb-like elements (30',30") to rotate about said first hinge portion alternately between an open configuration and a closed configuration, - a slide seat for said transmission stem, arranged to force said transmission stem to perform an alternated translational movement along said longitudinal axis of said elongated support, said transmission stem configured for reciprocating along a transmission axis which is aligned with said longitudinal axis, and in that said pin, which is integral to said transmission stem for both said two links, is arranged on said transmission axis of said transmission stem. - an elongated support configured to be grasped by an operator and having a longitudinal axis and an enlarged end portion that is widened with respect to the longitudinal axis; - two comb-like elements (30',30"), each comprising: - respective elongated base members (31',31") extending along respective base directions (37',37"); - respective arrays of fingers that extend from said respective elongated base members (31',31") on a same side, opposite to said elongated support, with respect to said respective elongated base members (31',31"), wherein each of said two comb-like elements (30',30") has a first hinge portion that is pivotally connected to said enlarged end portion, and a second hinge portion that is arranged at a lever distance from said first hinge portion; - respective elongated base members (31',31") extending along respective base directions (37',37"); - respective arrays of fingers that extend from said respective elongated base members (31',31") on a same side, opposite to said elongated support, with respect to said respective elongated base members (31',31"), - an actuation unit configured for actuating an alternating rotational movement of said comb-like elements (30',30") with respect to said enlarged end portion about said respective first hinge portions, wherein said actuation unit is mounted to said elongated support; - a movement transmission mechanism between said actuation unit and said two comb-like elements (30',30"), comprising two links, each pivotally connected to said second hinge portion of a respective comb-like element (30',30") of said two comb-like elements, - a transmission stem comprising: - a first end portion connected to said actuation unit; - a second end portion, opposite to said first end portion, connected to a pin arranged at said second end portion of said transmission stem; said transmission stem connected to a first end of each of said two links by said pin, so that said second end portion, through both said links, causes said comb-like elements (30',30") to rotate about said first hinge portion alternately between an open configuration and a closed configuration, - a first end portion connected to said actuation unit; - a second end portion, opposite to said first end portion, connected to a pin arranged at said second end portion of said transmission stem; - a slide seat for said transmission stem, arranged to force said transmission stem to perform an alternated translational movement along said longitudinal axis of said elongated support,