Method for manufacturing an object comprising the following steps: - inserting in a first forming container a quantity of a first material comprising particles having a shell made of thermoplastic material, which encapsulates a fluid that makes said particles expansible; - heating said first forming container to a first temperature such that to cause an expansion of the particles of said first material and a mechanic bonding among said particles; - cooling said first forming container, a first semi-finished product having geometrical shape at least partially defined by said first forming container being obtained following the heating and cooling of said first forming container, said first semi-finished product having a solid structure at least partially formed by solidified expanded and bonded particles of said first material, the expanded and bonded particles of said first material having a residual expansion capacity; further comprising the following steps: - covering, at least partially, said first semi-finished product with at least a second material; - inserting said first semi-finished product in a second forming container, said first semi-finished product being at least partially covered with said second material; - heating said second forming container to a second temperature higher than said first temperature such that to cause a further expansion of the expanded and bonded particles of said first material by exploiting the residual expansion capacity of said expanded and bonded particles and a consequent expansion of the volume of said first semi-finished product so that said first semi-finished product presses at least partially said second material against one or more walls of said second forming container; - cooling said second forming container, a second semi-finished product having geometrical shape at least partially defined by said second forming container being obtained following the heating and cooling of said second forming container, said second semi-finished product having a solid structure at least partially formed by at least a solidified layer of said second material. - inserting in a first forming container a quantity of a first material comprising particles having a shell made of thermoplastic material, which encapsulates a fluid that makes said particles expansible; - heating said first forming container to a first temperature such that to cause an expansion of the particles of said first material and a mechanic bonding among said particles; - cooling said first forming container, a first semi-finished product having geometrical shape at least partially defined by said first forming container being obtained following the heating and cooling of said first forming container, said first semi-finished product having a solid structure at least partially formed by solidified expanded and bonded particles of said first material, the expanded and bonded particles of said first material having a residual expansion capacity; - covering, at least partially, said first semi-finished product with at least a second material; - inserting said first semi-finished product in a second forming container, said first semi-finished product being at least partially covered with said second material; - heating said second forming container to a second temperature higher than said first temperature such that to cause a further expansion of the expanded and bonded particles of said first material by exploiting the residual expansion capacity of said expanded and bonded particles and a consequent expansion of the volume of said first semi-finished product so that said first semi-finished product presses at least partially said second material against one or more walls of said second forming container; - cooling said second forming container, a second semi-finished product having geometrical shape at least partially defined by said second forming container being obtained following the heating and cooling of said second forming container, said second semi-finished product having a solid structure at least partially formed by at least a solidified layer of said second material.