PARAFAC is a three mode factor analytic method developed by R.A. Harshman and is useful for data analysis. The fundamental idea says $${x_{ijk}} \approx \sum\limits_s^S {a_{is}}{b_{js}}{c_{ks}}$$ where xijk is given by measurement for i=1, 2…,I, j=1, 2,…, J, k = 1, 2,…, K; aisbjs, and cks are unknown solutions for the s-th factor, s=1, 2,…, S. However the computer program of PARAFAC developed by Harshman seems to require great skill to understand how to handle it and select the optimal solution through many steps. Here a new fool-proof algorithm not to require any skill is presented.