Under the new French law, French Angel Investors can deduct up to 75% of the money invested to their “ISF” tax, with a limit set up at €50 000.
http://www.minefe.gouv.fr/tepa/objectifs/obj_rub6.htm

Under the French law, 25% of the amount invested in cash in a “PME” could be deducted to their due tax amount, with a limit set up at €12000 for an individual.
http://www.legifrance.gouv.fr/WAspad/UnTexteDeJorf?numjo=ECOX0600160L

Angel investing in small business opportunities offers many tax benefits. For example, losses realized resulting from investments in start-up companies that fall under Internal Revenue Code, Section 1244(which defines "qualified small business tax treatment") are deductible against ordinary income taxes.One-half of any gains realized from investing in "qualified small businesses", under section 1202 of theIRS code, if held for a specific period of time, can be excluded from capital gains tax. Regardless of theholding period, any gains realized from a Section 1202 "qualified small business", qualifies for a 1045, tax free exchange into a new "qualified small business". (See your accountant for specific details.)For further details on Angel Investing guidelines, please refer to Internal Revenue Service or SecuritiesAnd Exchange Commission

In UK, there is a tax benefit program for Angel Investors under the Enterprise Investment Scheme (EIS).In order to qualify under the EIS Rules, businesses must be a "qualifying company": it must not be controlledby another organisation and must carry on a "qualifying trade" which includes most manufacturing and service businesses. For further details on the EIS program and guidelines, please refer to
http://www.inlandrevenue.gov.uk/pdfs/ir137.pdf