Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2022	Aug. 08, 2022
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Jun. 30, 2022
Entity File Number	001-40592
Entity Registrant Name	Rapid Micro Biosystems, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	20-8121647
Entity Address State Or Province	MA
Entity Address, Address Line One	1001 Pawtucket Boulevard West
Entity Address, Address Line Two	Suite 280
Entity Address, City or Town	Lowell
Entity Address, Postal Zip Code	01854
City Area Code	978
Local Phone Number	349-3200
Title of 12(b) Security	Class A common stock, $0.01 par value per share
Trading Symbol	RPID
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Central Index Key	0001380106
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q2
Amendment Flag	false
Common Class A
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		36,389,073
Common Class B
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		5,553,379