Consent of Independent Certified Public Accountants
We have issued our report dated April 28, 2000 accompanying the financial
statements of Insured Municipals Income Trust, 100th Insured Multi-Series as of
February 29, 2000, and for the period then ended, contained in this
Post-Effective Amendment No. 9 to Form S-6.
We consent to the use of the aforementioned report in the Post-Effective
Amendment and to the use of our name as it appears under the caption "Auditors".
Grant Thornton LLP
Chicago, Illinois
June 26, 2000
