We investigate in detail the magnetic properties and the critical exponents in terms of the magnetocaloric effect (MCE) of amorphous Fe40Ni38Mo4B18 alloy. The melt spinning method has been used to synthesize the amorphous alloy. The Curie-Weiss temperature and experimental moment determined from the Curie-Weiss law. Additionally, universal behaviour of phase transitions was also studied to assess magnetic phase ordering in this material. Such investigation exhibits that the phase transition from the FM to PM states is a second order. A phenomenological model is applied to describe the magnetocaloric effect (MCE) behaviour of compound under investigation. The critical exponents β, γ, δ, and n are found to be close to the 3D Heisenberg model. Our findings confirm the good correlation between the critical exponents and the MCE in this material.