"I'd like to state loud and clear: extremism of any kind hurts this country," Busch said in a speech to shareholders at Siemens's annual general meeting in Munich.
"Prosperity is based on progress and innovation, on exchanges and openness, on diversity and dependability - and above all on creative and committed people," he added.
"And this naturally includes all those who come to Germany and want to contribute themselves and their skills."
Although Busch did not explicitly mention Alternative for Germany (AfD) his comments could be seen as an attack on the far-right party, which is currently in second place in opinion polls behind the main opposition conservatives.
German companies and their CEOs are increasingly warning about the threat of right-wing extremism to Europe's largest economy following a report about a meeting where plans for mass deportations of citizens of foreign origin were discussed.
Siemens Energy supervisory board chairman Joe Kaeser last month warned of a resurgence of right-wing extremism in Germany, saying a policy of mass deportation was "absolutely disgusting".
The AfD has sought to distance itself from the deportation proposal aired at a meeting with right-wing radicals, saying it is not party policy. AfD deputy leader Peter Boehringer told Reuters last week accusations that the party harmed the economy were part of a "state and media campaign against the AfD".
But the report has sparked national outrage and concerns over Germany's attractiveness to foreign labour and investment.
Siemens currently employs around 88,000 people in Germany, its second biggest market after the United States, and is investing $1 billion in a new high tech production and research centre in Erlangen, near Nuremberg.
The company also reported its first quarter earnings on Thursday.
(Reporting by John Revill; Editing by Gareth Jones)
