A filling unit for contact or contactless filling an article with a pourable product, comprising: - a tank comprising, in turn, a first region fillable with said pourable product and a second region fillable with a first aeriform; and - at least one filling device; said filling device comprising, in turn,: - a first valve, which is set, in use, in a first open configuration in which it allows the fluidic connection between said first region of said tank and said article, so as to fill said article with said pourable product, or in a first closed configuration in which it prevents the fluidic connection between said first region and said article; - a first fluidic line for said first aeriform, which extends from said second region of said tank to an inner volume of said article in case of contact filling; - a second valve, which is set, in use, in a second open configuration, in which it allows the flow of said first aeriform along said first fluidic line, or in a second closed configuration, in which it prevents said aeriform from flowing along said first fluidic line; and - a control unit configured to set said first valve in said first closed configuration and said second valve in said second open configuration in case of contact filling, so as to pressurize said article before the filling thereof with said pourable product; and - at least one second fluidic line for said first aeriform and/or a second aeriform contained inside said article, which is distinct from said first fluidic line and extends from said inner volume of said article to a discharge area distinct from said tank; and - at least one third valve, which is selectively set, in use, in a third open configuration in which it allows the flow of said first aeriform and/or said second aeriform along said second fluidic line, or in a third closed configuration in which it prevents said first aeriform and/or second aeriform from flowing along said second fluidic line; said control unit being configured to set said first valve in said first open configuration and said third valve in said third open configuration in case of contact filling, so as to allow said first aeriform and/or a second aeriform contained in said article to be discharged from said article during the contact filling of said article; said filling unit further comprising: - a first chamber interposed along said first fluidic line; and - a second chamber interposed along said second fluidic line and distinct from said first chamber; the filing unit being characterized by further comprising a duct, which is interposed between said first fluidic line and said second fluidic line and is arranged outside said filling device; said duct being adapted to keep, in use, a given pressure difference between said first fluidic line and said second fluidic line; said filling unit further comprising: - a connection point, at which said second fluidic line and said duct are fluidly connected; said second fluidic line comprising a portion which is interposed between said second chamber and said connection point; and - a first means to create hydraulic loss, which is arranged along said portion and/or - a second means to create hydraulic loss, which is arranged along said duct. - a tank comprising, in turn, a first region fillable with said pourable product and a second region fillable with a first aeriform; and - at least one filling device; - a first valve, which is set, in use, in a first open configuration in which it allows the fluidic connection between said first region of said tank and said article, so as to fill said article with said pourable product, or in a first closed configuration in which it prevents the fluidic connection between said first region and said article; - a first fluidic line for said first aeriform, which extends from said second region of said tank to an inner volume of said article in case of contact filling; - a second valve, which is set, in use, in a second open configuration, in which it allows the flow of said first aeriform along said first fluidic line, or in a second closed configuration, in which it prevents said aeriform from flowing along said first fluidic line; and - a control unit configured to set said first valve in said first closed configuration and said second valve in said second open configuration in case of contact filling, so as to pressurize said article before the filling thereof with said pourable product; and - at least one second fluidic line for said first aeriform and/or a second aeriform contained inside said article, which is distinct from said first fluidic line and extends from said inner volume of said article to a discharge area distinct from said tank; and - at least one third valve, which is selectively set, in use, in a third open configuration in which it allows the flow of said first aeriform and/or said second aeriform along said second fluidic line, or in a third closed configuration in which it prevents said first aeriform and/or second aeriform from flowing along said second fluidic line; - a first chamber interposed along said first fluidic line; and - a second chamber interposed along said second fluidic line and distinct from said first chamber; - a connection point, at which said second fluidic line and said duct are fluidly connected; said second fluidic line comprising a portion which is interposed between said second chamber and said connection point; and - a first means to create hydraulic loss, which is arranged along said portion and/or - a second means to create hydraulic loss, which is arranged along said duct.