The invention concerns a device for performing a reaction or at least two reactions in parallel or in series, and for transferring a fluid flow, consisting of. an upper surface (2) and a lower surface (3) mutually linked by an edge (4); at least a duct (5) wherein a fluid flow (F1) can be generated by means transferring at least one sample (6) to be treated and/or analysed, and at least a valve (8) incorporated in each duct (4) for directing each sample (6) thereby controlling the transfers, reactions and analyses in the device. Each valve (8) consists of two means (9 and 10) integral with the device, the first means (9) being mobile between an inoperative position wherein the fluid transfer (6) is possible and an active position wherein said transfer cannot take place, and the second means (10) being mobile between a position wherein it is not in contact with said first means (9) and an active position wherein it deforms the first means (9) and it is activated by an actuator external to the device.