Diploma Regulatory News (DPLM)

FOR IMMEDIATE RELEASE 12 CHARTERHOUSE SQUARE, LONDON EC1M 6AX

TELEPHONE: +44 (0)20 7549 5700

FACSIMILE: +44 (0)20 7549 5715

27 May 2010

DIPLOMA PLC - DIRECTORS' INTERESTS IN SHARES

Diploma PLC has been notified today that Mr I Henderson, a Director of the Company, has disposed of 150,000 ordinary shares of the Company at 223.0 pence per share. Mr Henderson retains 416,604 ordinary shares in the Company.

For further enquiries please contact:

Nigel Lingwood, Group Finance Director 020 7549 5705