The present invention provides a biological culture growth and observation device (1) comprising a cup-shaped tray (2) for containing or receiving a growth medium for said biological culture and a cap (4) which matches said tray (2) and which can be snapped on and off said tray (2), characterized in that said cap (4) and tray (2) are provided with means (5) to snap on/off said cap (4) on/off the inner walls (6) of said tray (2) and in that said cup-shaped tray (2) is realized with walls (7) having a first circumferential edge (8) on which a removable seal (10) can be fixed to cover the surface of said edge (8) and the cap (4) snapped on the tray (2) before the first use of the device (1).