Abstract: A failure diagnosis device, program and storage medium are provided, which are capable of automatically generating FTA and/or FMEA from MFM. An FTA generating section generates an FTA knowledge by reading out, from an HD, an MFM knowledge systematically and organically representing goals, functions, relations between the functions, relations between the functions and goals, and relations between the functions and components realizing the functions; an MFM attendant knowledge including a component behavior knowledge representing relations between failures and behaviors of components when failure occurs in the component; and an influence-repercussion rule defining the influence exerting when the function is changed. An FMEA generating section generates an FMEA knowledge by reading out the MFM knowledge, the MFM attendant knowledge, and the influence-repercussion rule from the HD.