There were so many complex reasons that the Industrial Revolution occurred first in Great Britain that it is impossible to discuss them here in great detail. Briefly, Great Britain had a ready supply of cheap labor due to the success of the enclosure movement. It also had a steady flow of raw materials from its American colonies, who also served as secure markets (even for a few decades after the American Revolution) for British manufactures. These markets were made secure by the most powerful navy in the world, and the utter defeat of the French in the Seven Years War. Great Britain also had a secure financial infrastructure, including a centralized, government-backed bank that could keep capital flowing to entrepreneurs, many of whom became highly-placed government officials.
The island nation also did not experience the turmoil of the French Revolution, in fact the need to supply armies during the almost constant warfare of the eighteenth and early nineteenth centuries was another major contributing factor to the emergence of industry in England. Britain had a representative government dominated by a gentry class that invested heavily in industry, and they thus passed legislation friendly to its development. It had strong patent laws and a long-standing legal tradition of the sanctity of property. Historians used to even argue that Britons had a peculiarly Protestant work ethic that valorized profit-making but eschewed display of wealth that could be better employed as capital for making future profits.
Finally, Britain had natural advantages. It had plenty of rivers to run early water-powered mills, and to ship their goods to distant markets. Coal, the lifeblood of the early industrial revolution, existed in abundance in Wales and other regions in Great Britain.