This is PART I of a two part proposal investigating the
 very low mass population of the Pleiades open cluster.
 PART II has been submitted separately.

 Hambly, Hawkins & Jameson (1991, MNRAS, 253, 1) carried out
 a deep proper motion survey of the Pleiades discovering a
 large population of low mass stars.  Follow-up infrared
 photometry (Steele, Jameson & Hambly, 1993, MNRAS, 263, 647)
 showed that around 20 of the Pleiades objects were good
 brown dwarf candidates (ie. had M<0.08 M_solar).  We propose
 to use ISOCAM to image a sample of our low mass stars and
 brown dwarf candidates at 7.5 and 12 microns.  This will
 have four principal aims:

 1.  To search for possible low mass companions.
 2.  To search for evidence of a vestigial formation disk.
 3.  To obtain a better estimate of L_bol for these objects.
 4.  To obtain a better estimate of T_eff for these objects.

 The scientific return of the proposed observations is high,
 and the observations of these very faint sources may only
 be made using ISO at the wavelengths in question.