A method of manufacturing a microfluidic system or microfluidic device having at least one channel includes providing a base sheet, providing a deformable intermediate layer, providing a cover film, and laminating the base sheet, the intermediate layer and the cover film so that a back surface of the intermediate layer is attached to a front surface of the base sheet and a back surface of the cover film is attached to a front surface of the intermediate layer opposite to the back surface thereof, thereby forming a laminate comprising the base sheet, the intermediate layer and the cover film. Further, the method includes applying pressure to the front surface of the intermediate layer through the cover film so as to deform the intermediate layer, thereby forming the at least one channel. The invention also relates to a microfluidic system or microfluidic device) manufactured by this method.