Document and Entity Information	3 Months Ended
	Sep. 30, 2014	Oct. 21, 2014
Document and Entity Information
Entity Registrant Name	ASPEN TECHNOLOGY INC /DE/
Entity Central Index Key	0000929940
Document Type	10-Q
Document Period End Date	Sep. 30, 2014
Amendment Flag	false
Current Fiscal Year End Date	--09-30
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		90,471,242
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1